W3C home > Mailing lists > Public > www-tag@w3.org > May 2006

Re: [metadataInURI-31] New editors draft for Metadata In URIs Finding

From: Frank Manola <fmanola@acm.org>
Date: Tue, 16 May 2006 11:55:52 -0400
Message-ID: <4469F608.5070306@acm.org>
To: noah_mendelsohn@us.ibm.com
CC: www-tag@w3.org

noah_mendelsohn@us.ibm.com wrote:
> Frank Manola writes:
> 

snip

> 
>> In Section 2.2:
>>
>>> Bob is using the original URI for more than its intended purpose, 
>>> which is to identify the Chicago weather page. Instead, he's 
>>> inferring from it information about the structure of a Web site that,
>>>  he guesses, might use a uniform naming convention for the weather in
>>>  lots of cities. So, when Bob tries the Boston URI, he has to be 
>>> prepared for the possibility that his guess will prove wrong: Web 
>>> architecture does not guarantee that the retrieved page, if there is 
>>> one, has the weather for Boston, or indeed that it contains any 
>>> weather report at all. Even if it does, there is no assurance that it
>>>  is current weather, that it is intended for reliable use by 
>>> consumers, etc. Bob has seen an advertisement listing just the 
>>> Chicago URI, and that is the only one for which the URI authority has
>>>  taken specific responsibility.
>> I don't understand the reference to what "Web architecture" guarantees
>> in this paragraph.  I don't think "Web architecture" guarantees that the
>> page retrieved from http://example.org/weather/Chicago has the weather
>> for Chicago either.  In the case of Chicago, it's the URI authority that
>> (as you note) states ("guarantees" seems a bit strong) that
>> http://example.org/weather/Chicago will return a Chicago weather page.
>> Similarly, it's the URI authority (rather than Web architecture) that
>> hasn't made any claims about providing information on Boston weather.
> 
> Yes, I see your point.  I think it depends on how broadly you view the 
> word "architecture".  You're taking a narrow view, which I think has some 
> merit:  i.e., you seem to be saying that the Web Architecture deals only 
> with the overt, computer-based mechanisms of the Web.  I took a somewhat 
> broader view, which is that the Web is a social system as well as a system 
> of protocols and bits.  The architecture includes, at least to some 
> degree, the agreements that we as people make in using and deploying the 
> Web in a style that will scale well and give good results. 
> 
>>From this perspective, I think there is a point of view that if the 
> authority for a resource makes a statement about a resource, either by 
> writing that statement on the side of a bus as in this example, or by 
> writing it in RDF, that the statement can be discussed by Web Architecture 
> as I have done.  The Web Architecture clearly has a notion of an authority 
> responsible for the assignment of a URI, and I think it's plausible to 
> state that their representations about the resource carry weight in this 
> larger architectural sense.
> 
> I do understand both points of view on this.  I'll give it some thought, 
> and see what other commentators think (but please, I think this is worth a 
> modest number of messages on www-tag, but not a permathread!)  Thanks.

OK, I understand what you're trying to do now.  But I think if you want 
to go in this direction, you ought to elaborate on this (e.g., saying 
something like what you've just said) a bit more in the text.  I was 
coming from the TAG's "The Architecture of the World Wide Web", which I 
think uses "Web architecture" in a somewhat narrower sense.  Even if you 
want to take a more expansive view of "architecture" in this document, I 
think it'll be important to clarify the distinction between what's 
guaranteed by the "architecture" in the narrower sense, and what's 
guaranteed by the "achitecture" in the more expansive sense.

> 
>>> "For the best weather information for your city, visit
>>> http://example.org/weather/your-city-name-here."
>>>
>>> Reading that advertisement, Bob is entitled to assume that any
>>> weather report retrieved from such a URI is both trustworthy and
>>> current.
>> The appearance of words like "entitled", "trustworthy", and "current" 
>> seem to go too far in this context.  The subject here seems to be the 
>> authority having documented its URI assignment policy (sort of) in the 
>> ad, not the quality of the reports (trustworthy, loyal, helpful, 
>> friendly, courteous, ...!). 
> 
> On this I don't think I agree.  The ad on the bus did more than document 
> an assignment policy;  it claimed that the weather available at the URI 
> was "the best".   That establishes expectations (I'm presuming we all 
> believe that advertisement was authorized by the URI assignment authority, 
> which seems a reasonable assumption.) 
> 

Actually, I was trying to make two points, but clearly I didn't do a 
very good job.  You've addressed one of the points, the bit about "the 
best", which I'll get back to in a bit.

However, the other point (and actually the more straightforward one) is 
that the section starts off talking about the value of *documenting the 
URI assignment policy*, and the ad

"For the best weather information for your city, visit
http://example.org/weather/your-city-name-here."

is given as an example of documenting that assignment policy.  But the 
following text

"Reading that advertisement, Bob is entitled to assume that any
weather report retrieved from such a URI is both trustworthy and
current."

doesn't talk about what Bob can assume based on the fact that the ad 
provides information about URI assignment policy.  It only talks about 
what Bob can assume based on the use of "best weather information" in 
the ad (and it doesn't explicitly connect what Bob is entitled to assume 
about the trustworthiness of the weather report with the fact that 
"best" appeared in the ad).  In other words, whether or not you want to 
talk about what Bob can assume about the *quality* of the weather 
report, I think you ought to at least say something like:

"Reading that advertisement, Bob can reasonably assume that he can get a 
weather report for a specific city at a URI created by substituting the 
city name into the URI pattern 
http://example.org/weather/your-city-name-here."

to nail down the point that the authority has documented its URI 
assignment policy in the ad, and Bob can reasonably make use of that 
information in obtaining weather reports on arbitrary cities by 
constructing the appropriate URIs.

If you want to go on and point out that the authority has *also* made 
claims about the *quality* of the weather reports that can be obtained 
at those URIs, and that Bob ought to be able to rely on those claims, I 
think you should be more explicit about that, e.g., with some additional 
text like:

"Moreover, the advertisement claims that the weather information 
obtainable at those URIs is "the best", and hence Bob can reasonably 
assume that any weather report retrieved from such a URI is both 
trustworthy and current."

On the expectations that Bob may have based on these reports being 
claimed as "the best" by the authority, this reminds me of the intensive 
discussion a few years ago on the "social meaning of RDF".  I think 
there may be some merit in bringing this kind of thing up but, if you 
*are* going to bring it up, I think the issue requires more explicit 
discussion in the text than it currently gets.

--Frank
Received on Tuesday, 16 May 2006 15:52:55 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Thursday, 26 April 2012 12:47:40 GMT